CNDP1 and diabetes mellitus: In keeping with the forgoing that the genotype frequency of the homozygous (CTG)5 genotype is low in the Chinese Han population and that high CN-1 concentration might inflict a risk to develop DKD, we sought to address if other CNDP1 genotypes are posing a risk for DKD in the Chinese Han population, which factors influence CN-1 concentrations in serum and/or urine, to what extent serum and urinary CN-1 are associated with progression of DKD and finally if CN-1 expression is influenced by diabetes-associated inflammation.